Engine Overheat - need advice

[digthewells]

First off, I'm new at all of this. I've been looking through the forums and you guys seem to really know your stuff and are very helpful (butter you up).

He's my story and I just need some advise...

I just bought a 1991 Seadoo SP with the yellow engine. It ran fine, but it was very hard to start. I usually had to use starter fluid to get it going. This doesn't seem right to me (compression or vaccum issue?).

Anyway, I took it out and the engine over heated and locked up. I did not realize the temp sensor was not working. Anyway, a short time later it unlocked, but now I am not getting any fuel it appears.

The compression in both cylinders after the overheat was about 120. I tore the engine down just to look at the damage to the pistons and cylinders. The one that locked up is a little scored, but the other is fine. Head and everything look good.

Where do I go from here? I don't just want to patch it, I want to fix it. I think I should get the cylinders bored and get a top-end rebuild kit and replace the pistons. There is not much play in the rods, but I don't know how they should be to know if its worth doing this or just rebuilding the entire engine and be done with it. I don't want to spend several $100 when I can put a few in it and have it fixed, but I don't want to put it together and still have problems.

I know it's a tough call, but anyone with experience in this?

Thanks!

 

[nswillin]

Is the engine locked up or not? You said it locked up and then said it unlocked and then you said one cylinder was locked up.

If nothing is locked up and your compression is 120, your probably ok with the topend, for now. First thing is, find out why it over heated. Second thing is, if the engine actually locked up from over heating then there's no telling on how much damage was done to the bottom end.

Take the cover off the shaft at the PTO and see how smooth the shaft turns, counter clockwise. The bearing probally got real hot and your crank could have warped or twisted.

A lot to consider if you plan on diving into this.

 

[digthewells]

Thanks for the info. It did lockup, but after cooling it unlocked. When I took it apart i saw the cylinder that locked up (but unlocked). It is scored up. The crank turns nicely and there is no roughness. I am getting the cylinders bored and doing the top end. After that is together I may rebuild carb if I need to.

I appreciate your input.

 

[bah1971]

mine overheated because the carbs were bad which caused it to run lean and overheat. carb kits are not expensive and you don't need any special tools.